Lots of things happened over Christmas. Via the wonders of 3D, the Queen leapt out of the UK's TVs like a particularly horrifying Ring ghost; I ate all the chocolate, ALL OF THE CHOCOLATE; and Nifflas released the third in his truly wonderful Knytt series. Knytt Underground (opens in new tab) continues the atmospheric, oft-tricky, exploratory platforming his games are known for, this time with new abilities, a whopping 1,800 rooms, and Dark Souls-style apocalyptic bell-ringing. You'll need $14.99, plus a PC or Mac (the console version's already out, while the Linux one's in beta), and here's that demo (opens in new tab) you were just about to ask for.
If you're wondering what your character's motivation is for jumping to higher platforms, here's the skinny from the website: "Mi Sprocket is a sprite who develops special powers as she embarks upon a quest to ring the six bells of fate; which if not rung every six hundred years will begin a chain reaction that will obliterate the world!" There seems to be more dialogue here than in the previous Knytts, but just as much atmosphere, this time (mostly) in a series of spooky and beautiful caves. Hark at these yourself in the following video: